The field of the present invention is ophthalmic monitoring systems and, more particularly, scleral and corneal contact lenses for use with such systems.
Recently, substantial attention has been directed to the use of pupil monitoring systems for use in medical applications. One such system is described in U.S. Pat. No. 5,297,554, which is entitled "Device for Use in Real-Time Monitoring of Human or Animal Bodily Function" (hereinafter "the '554 patent"). The system described in the '554 patent employs a scleral contact lens for locating and supporting on the eye of a patient an optical system including at least one discrete light source and one discrete receiver. The described scleral contact lens has a first surface which conforms to the sclera and bulbar conjunctive tissue of a patient's eye, and a second surface including a tubular extension that provides a mount for the optical system.
While the system described in the '554 patent may be useful in short term pupil monitoring applications, its usefulness for long term pupil monitoring applications is questionable. The reason for this is that the combination of the scleral contact lens and optical monitoring system is quite bulky. Moreover, it is difficult to assess how long a patient's eye could tolerate having a device such as that described in the '554 patent mounted thereon.
Another device for monitoring the size of a patient's pupil is described in U.S. Pat. No. 4,007,980, entitled "Device for the Measurement of the Size of an Eye Pupil" (hereinafter "the '980 patent") . The device described in the '980 patent is also quite bulky and likely could not be tolerated by a patient's eye for substantial periods of time.
In view of the foregoing, it is believed that those skilled in the art would find a scleral contact lens that could be easily manipulated and left on a patient's eye for a substantial period of time to be quite useful.